Method for preparing biological coal through organic solid waste coupled biomass pyrolysis
Through the coordinated pyrolysis of organic solid waste and biomass, mechanical physical dehydration and multi-layer split furnace treatment, the problems of low added value and high energy consumption of organic solid waste treatment products are solved, and high calorific value biocoal is prepared, which broadens the application scenarios and improves economic value.
Patent Information
- Application Number
- CN202510545138.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-28
- Publication Date
- 2025-08-15
AI Technical Summary
The added value of existing organic solid waste treatment products is low and the application scenario is narrow; the pyrolysis energy consumption of a single biomass is high, and the synergistic effect of organic solid waste and biomass is not fully utilized alone leads to low pyrolysis efficiency and insufficient product calorific value.
Through the coordinated pyrolysis of organic solid waste and biomass, mechanical physical dehydration is used to reduce the moisture content of organic solid waste, and then mix, dry, distillate and cool in a multi-layer split furnace to achieve self-heating equilibrium and prepare high-calorie biocoal.
The system's self-heating balance is achieved, energy consumption is reduced by more than 40%, the product biocoal has a high calorific value, widens application scenarios, and can replace fossil fuels or serve as a precursor of carbon-based materials, with significant economic value.
Smart Images
Figure CN120484832A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of organic solid waste resource utilization and biomass energy efficient conversion, and in particular to a method for preparing biocoal by coupling organic solid waste with biomass pyrolysis. Background Art
[0002] Organic solid waste originates from all aspects of national production and life: domestic garbage generated in daily life, sludge remaining after domestic sewage treatment, medical waste such as IV tubes and surgical residues generated by the medical industry, leftovers from garment factories, and residues from recycled paper mills. Organic solid waste has a high moisture content (usually over 50%), low calorific value, and contains pollutants such as heavy metals and pathogens. Traditional disposal methods (landfill and incineration) can easily cause soil and water pollution and greenhouse gas emissions, resulting in secondary pollution. Existing organic solid waste treatment methods (such as composting and anaerobic digestion) have low added value products and are difficult to apply on a large scale, resulting in an incomplete organic solid waste disposal industry chain.
[0003] Biomass (such as straw, agricultural and forestry waste, etc.) has the characteristics of high volatile matter (60%-80%) and low ash content (<5%), but existing biomass pyrolysis technology still has the following defects: the biomass has a high moisture content, single biomass pyrolysis requires additional drying, and energy consumption is high (accounting for 30%-50% of the total processing cost); although the biocoal obtained by biomass pyrolysis has a high calorific value, the raw material source is single, and its large-scale application is limited.
[0004] How to achieve the coordinated optimization of organic solid waste reduction, harmlessness and resource utilization through the synergistic pyrolysis of organic solid waste and biomass has become the core technical problem in the current field of organic solid waste treatment. Summary of the Invention
[0005] The purpose of the present invention is to solve the problems of low added value and narrow application scenarios of existing organic solid waste treatment products; high energy consumption of single biomass pyrolysis, and insufficient synergistic effect of separate treatment of organic solid waste and biomass, resulting in low pyrolysis efficiency and insufficient calorific value of products. A method for preparing biocoal by coupling pyrolysis of organic solid waste with biomass is provided. By coupling pyrolysis and dry distillation of organic solid waste with biomass, self-thermal balance of the system can be achieved without the need for external heating. The coupled pyrolysis and dry distillation product (biocoal) has both high calorific value and stable physical and chemical properties, can replace fossil fuels or serve as a precursor of carbon-based materials, and has significant economic value.
[0006] The technical solution adopted by the present invention to solve its technical problem is:
[0007] A method for preparing biocoal by coupling organic solid waste with biomass pyrolysis comprises the following steps:
[0008] S1. Raw material pretreatment: Organic solid waste with a dry basis calorific value of 900-4200kcal / kg is mechanically and physically dehydrated to a moisture content of <50% as the organic solid waste raw material. Sewage plant sludge is preferred as the organic solid waste, as it is widely applicable and can also solve the solid waste problems of municipal / industrial sewage plants. Mechanical and physical dehydration eliminates the need for heat drying, reducing energy consumption in the drying stage. Biomass with a moisture content of 12%-40% and a dry basis calorific value of 3500-4500kcal / kg (including agricultural and forestry waste such as sawdust and straw, as well as livestock manure, Chinese herbal medicine residue, etc.) is selected as the biomass raw material. Sawdust with a moisture content of 12-20% and a dry basis low calorific value of 3600-4200kcal / kg is preferred. It has low acquisition cost and abundant resources, especially discarded furniture and building materials in the process of urban renewal, which can be used as a source of organic matter.
[0009] S2. Raw material mixing: organic solid waste raw materials and biomass raw materials are mixed into mixed raw materials according to calorific value and moisture content. The usage ratio of organic solid waste raw materials and biomass raw materials is such that the moisture content of the mixed raw materials is less than 40% and the average calorific value is greater than 2400Kcal / kg, thereby ensuring the self-heating balance of the pyrolysis process.
[0010] S3. Drying: The mixed raw materials enter the drying zone on the upper layer of the multi-layer split furnace and are dried at a temperature of 250-400°C to a moisture content of <5% to obtain dry materials;
[0011] S4, dry distillation: The dried material enters the dry distillation zone in the middle layer of the multi-layer split furnace, and the temperature of the dry distillation zone is controlled at 400-600℃. In an oxygen-deficient atmosphere, it undergoes deep drying, organic matter devolatization, organic matter chain scission carbonization and carbonization molding processes to obtain dry distillation material. The volatile matter (such as cellulose and hemicellulose) in the biomass is rapidly cracked to release heat, which offsets the energy consumption required for the evaporation of water in the material.
[0012] S5. Cooling: The dry distillation material enters the cooling zone in the lower layer of the multi-layer split furnace and is gradually cooled to below 60°C in an oxygen-free atmosphere to obtain bio-coal. The dry distillation material enters the cooling zone for natural cooling in an oxygen-free atmosphere. Due to the residual temperature and energy of the material, the organic matter chain scission carbonization and carbonization forming process will continue in a time sequence in the oxygen-free atmosphere, thereby increasing the fixed carbon content per unit volume of the product.
[0013] As a further description of the above technical solution, in step S1, the organic solid waste refers to municipal, printing and dyeing plant or sewage treatment plant sludge with a dry basis calorific value ≥900kcal / kg, and the biomass refers to sawdust or straw with a moisture content ≤25% and a dry basis lower calorific value ≥3500kcal / kg; in step S2, the mass ratio of the organic solid waste raw material to the biomass raw material is 2:(1-6).
[0014] As a further description of the above technical solution, the temperature of the drying zone and the distillation zone is adjusted by a heating and temperature control system external to the multi-layer split furnace. The heating and temperature control system is connected to one or more burners, and the exhaust gas outlet of the burner is connected to the exhaust gas purification system.
[0015] As a further description of the above technical solution, the retorting zone is provided with a steam atomization injection interface, which can timely control the reaction temperature of the retorting zone to release and cool down according to the intensity of the reaction in the furnace to avoid over-temperature reaction.
[0016] As a further description of the above technical solution, the pyrolysis tail gas (containing combustible gases such as CO, CH4, H2, etc.) discharged from the air outlet of the drying area is purified and then transported to the burner for secondary combustion and reuse.
[0017] As a further description of the above technical solution, the exhaust gas discharged from the cooling zone outlet is fully burned by the burner to reduce the concentration of combustible gas, and then purified by the exhaust gas purification system to be discharged without pollution.
[0018] As a further description of the above technical solution, the drying zone and the retorting zone are composed of one or more standard modules, each of which is provided with a feed port, a discharge port and a combustion interface. The heating and temperature control system is connected to each standard module pipeline to control the temperature of each standard module, and the material stays in each standard module for 4-10 minutes.
[0019] As a further description of the above technical solution, the cooling zone is also composed of one or more standard cooling modules, each of which is provided with a feed port, a discharge port and a combustion interface, and the material stays in each standard cooling module for 4-10 minutes. The material after dry distillation enters the cooling zone for natural cooling in an oxygen-free atmosphere. Due to the residual temperature and energy of the material, the organic matter chain scission carbonization and carbonization molding process will continue to occur in sequence in an oxygen-free atmosphere, thereby increasing the fixed carbon content per unit volume of the product. In addition, the temperature of the dry distillation material is high. If there is not enough cooling residence reaction time, thermal decomposition and dry distillation will continue to occur, which will cause the carbonized sludge to be prone to spontaneous combustion.
[0020] As a further description of the above technical solution, the cooling zone is also connected to a water-cooled cooler under an external oxygen-free atmosphere. A large amount of continuous cooling water takes away the heat of the material through the material pipe wall. The direction of movement of the cooling water is opposite to the direction of movement of the material, so that the biocoal discharged from the cooling zone is further cooled to a temperature below 60°C through the water-cooled cooler.
[0021] The beneficial effects of the present invention are:
[0022] 1. Directly utilize the moisture content of organic solid waste and the low moisture content of biomass, and optimize the ratio of organic solid waste raw materials and biomass raw materials according to calorific value and moisture content. The high volatile matter in biomass can provide the heat required for pyrolysis and distillation, achieving self-heating balance without the need for external heat source, and reducing energy consumption by more than 40%.
[0023] 2. The calorific value of the coupled pyrolysis distillation product (biocoal) can reach 3600kcal / kg, the sulfur content is <0.3%, and the ash content is <24%. Its performance is significantly better than traditional organic solid waste products, which broadens the application scenarios. It can replace coal (reducing CO2 emissions by ≥1.5 tons / ton of biocoal) or be used to prepare high-value carbon materials.
[0024] 3. Every ton of organic solid waste processed can produce 0.3-0.5 tons of biocoal, and the comprehensive income is increased by 200-300 yuan / ton; it reduces landfill land and greenhouse gas emissions, and has both economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a schematic diagram of the multi-layer split furnace and its heating and temperature control system in the present invention;
[0026] Figure 2 This is a flow chart of the method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to the present invention. DETAILED DESCRIPTION
[0027] To make the above contents, objectives, and beneficial effects of the present invention more clearly understood, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings. The following description sets forth many specific details to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar modifications without violating the scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.
[0028] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention pertains. The terms used herein in the specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the relevant listed items.
[0029] like Figure 1As shown, the present invention provides a method for preparing biocoal by coupling pyrolysis of organic solid waste with biomass, wherein coupled pyrolysis and dry distillation of mixed raw materials are achieved through a multi-layer split furnace, and the multi-layer split furnace includes a drying zone, a dry distillation zone and a cooling zone from top to bottom. The temperatures of the drying zone and the dry distillation zone are adjusted by a heat supply and temperature control system external to the multi-layer split furnace, and the heat supply and temperature control system is connected to one or more burners, and the exhaust gas outlet of the burner is connected to the exhaust gas purification system for harmless emission after combustion exhaust purification. The burner air supply can use cold air or hot air, wherein hot air can better reduce energy consumption.
[0030] The air outlet on the upper layer of the drying area is connected to the dust collector, and the exhaust port of the dust collector is connected to the burner of the heating and temperature control system, which is used to purify and remove the pyrolysis exhaust gas discharged from the drying area outlet for secondary combustion.
[0031] The retorting area is equipped with a steam atomization injection interface, which can timely control the reaction temperature of the retorting area to release and cool down according to the intensity of the reaction in the furnace to avoid over-temperature reaction.
[0032] The cooling zone is connected to an external water-cooled cooler in an oxygen-free atmosphere. A large amount of cooling water continuously flows through the material pipe wall, removing heat from the material. The cooling water flows in the opposite direction of the material, further cooling the bio-coal discharged from the cooling zone to below 60°C through the water-cooled cooler. The lower air outlet of the cooling zone is connected to a burner, which is used to burn the exhaust gas discharged from the cooling zone outlet at high temperature, reducing the concentration of combustible gases. The exhaust gas is then purified by the exhaust gas purification system and discharged harmlessly.
[0033] Both the drying and retorting zones are composed of multiple standard modules, each equipped with a feed inlet, a discharge port, a combustion interface, and an observation port. The heating and temperature control system is connected to the pipes of each standard module to control its temperature. Specifically, the drying zone consists of the first, second, and third drying modules, from top to bottom. The temperature of the first drying module is controlled at 250-350°C, with a material residence time of 4-10 minutes; the temperature of the second drying module is 300-400°C, with a material residence time of 4-10 minutes; and the temperature of the third drying module is 350-400°C, with a material residence time of 4-10 minutes. The retort zone consists of the first, second, and third retort modules, arranged from top to bottom. The first retort module operates at a temperature of 400-450°C, with a residence time of 4-10 minutes; the second module operates at a temperature of 450-510°C, with a residence time of 4-10 minutes; and the third module operates at a temperature of 520-580°C, with a residence time of 4-10 minutes. When the pyrolysis retort temperature exceeds 600°C, the decomposition rate of organic matter does not change linearly with increasing temperature. The source of temperature is heat consumption. From an economic perspective, ensuring sufficient residence time at a retort temperature below 600°C allows for full decomposition of organic matter.
[0034] The cooling zone is also composed of multiple standard cooling modules, each equipped with a feed inlet, a discharge port, and a combustion interface. Specifically, the cooling zone consists of the first, second, and third cooling modules, from top to bottom. The temperature of the first cooling module is 300-650°C, with a material residence time of 4-10 minutes; the temperature of the second cooling module is 200-400°C, with a material residence time of 4-10 minutes; and the temperature of the third cooling module is 150-300°C, with a material residence time of 4-10 minutes. The retorted material enters the cooling zone for natural cooling in an oxygen-free atmosphere. Due to the residual temperature and energy in the material, the organic matter chain scission and carbonization process will continue in an oxygen-free atmosphere, increasing the fixed carbon content per unit volume of the product. Furthermore, the temperature of the retorted material is relatively high. Without sufficient cooling and reaction time, pyrolysis and retorting will continue, making the carbonized sludge susceptible to spontaneous combustion.
[0035] like Figure 2 As shown in FIG, the method for preparing bio-coal by coupling organic solid waste with biomass pyrolysis of the present invention comprises the following steps:
[0036] S1. Raw material pretreatment: Organic solid waste with a dry basis calorific value of 900-4200 kcal / kg is mechanically and physically dehydrated to a moisture content of <50% as the organic solid waste raw material; biomass with a moisture content of 12%-40% and a dry basis calorific value of 3500-4500 kcal / kg is selected as the biomass raw material, among which the organic solid waste is preferably municipal sludge, printing and dyeing plant or sewage treatment plant sludge with a dry basis calorific value ≥900 kcal / kg; biomass is preferably wood chips or straw with a moisture content ≤25% and a dry basis lower calorific value ≥3500 kcal / kg.
[0037] S2. Raw material mixing: organic solid waste raw materials and biomass raw materials are mixed into a mixed raw material according to calorific value and moisture content. The amount ratio of organic solid waste raw materials to biomass raw materials is such that the moisture content of the mixed raw materials is less than 40% and the average calorific value is ≥2400Kcal / kg, thereby ensuring the self-heating balance of the pyrolysis process. The preferred mass ratio of organic solid waste raw materials to biomass raw materials is 2:(1-6).
[0038] S3. Drying: The mixed raw materials enter the drying area on the upper layer of the multi-layer split furnace. The external heating and temperature control system of the multi-layer split furnace controls the temperature of the first drying module in the drying area to 250-350°C, the temperature of the second drying module to 300-400°C, and the temperature of the third drying module to 350-400°C. The mixed raw materials stay in the first drying module, the second drying module, and the third drying module for 4-10 minutes respectively. The mixed raw materials are dried to a moisture content of <5% to obtain dry materials. The pyrolysis exhaust (containing combustible gases such as CO, CH4, H2, etc.) discharged from the air outlet on the upper layer of the drying area is transported to the burner of the heating and temperature control system for secondary combustion and reuse.
[0039] S4, dry distillation: the dry material enters the dry distillation zone in the middle layer of the multi-layer split furnace. The heat supply and temperature control system outside the multi-layer split furnace controls the temperature of the first dry distillation module in the dry distillation zone to 400-450°C, the temperature of the second dry distillation module to 450-510°C, and the temperature of the third dry distillation module to 520-580°C. The dry material stays in the first dry distillation module, the second dry distillation module and the third dry distillation module for 4-10 minutes respectively. In an oxygen-deficient atmosphere, it undergoes deep drying, organic matter removal and volatilization, organic matter chain scission carbonization and carbonization molding processes to obtain dry distillation materials. The volatile matter (such as cellulose and hemicellulose) in the biomass is rapidly cracked to release heat, which offsets the energy consumption required for the evaporation of water in the material. When the temperature in the furnace is too high and the reaction is too intense, the steam atomization injection interface provided in the dry distillation zone is sprayed with atomized steam to release and cool the reaction temperature in the dry distillation zone to avoid over-temperature reaction.
[0040] S5. Cooling: The retorted material enters the cooling zone in the lower layer of the multi-layer split furnace and is gradually cooled to below 60°C in an oxygen-free atmosphere, producing biocoal. Specifically, the first cooling module maintains a temperature of 300-650°C with a residence time of 4-10 minutes; the second cooling module maintains a temperature of 200-400°C with a residence time of 4-10 minutes; and the third cooling module maintains a temperature of 150-300°C with a residence time of 4-10 minutes. The retorted material enters the cooling zone for natural cooling in an oxygen-free atmosphere. Due to the residual temperature and energy in the material, the organic matter chain scission and carbonization process continues in this oxygen-free atmosphere, increasing the fixed carbon content per unit volume of the product. The exhaust gas from the cooling zone outlet is fully combusted in a burner to reduce the concentration of combustible gas. It is then purified by an exhaust gas purification system for pollution-free discharge. The biocoal discharged from the cooling zone is further cooled in a water-cooled chiller to below 60°C, producing the biocoal product.
[0041] Application Example 1
[0042] Organic solid waste raw materials: municipal sludge, moisture content 75%, dry basis calorific value 1200kcal / kg, mechanically dehydrated to a moisture content of 50%.
[0043] Biomass raw materials: miscellaneous wood sawdust, moisture content 20%, dry basis calorific value 3900Kcal / kg.
[0044] Mixing ratio: municipal sludge: sawdust = 1:1.
[0045] Multi-layer split furnace pyrolysis and distillation parameters:
[0046] Drying zone: consists of three drying modules. The first drying module has a temperature of 250-280°C and a residence time of 6 minutes. The second drying module has a temperature of 300-330°C and a residence time of 6 minutes. The third drying module has a temperature of 360-400°C and a residence time of 6 minutes.
[0047] Retort zone: includes three retort modules, the first retort module temperature is 420-460℃, the residence time is 6 minutes; the second retort module temperature is 480-550℃, the residence time is 6 minutes; the third retort module temperature is 550-580℃, the residence time is 6 minutes.
[0048] Cooling zone: consists of three cooling modules. The first cooling module has a temperature of 560-400°C and a residence time of 6 minutes. The second cooling module has a temperature of 350-260°C and a residence time of 6 minutes. The third cooling module has a temperature of 220-150°C and a residence time of 6 minutes.
[0049] Results: The calorific value of biocoal is 3200Kcal / kg, fixed carbon is 61%, ash is 18%, and moisture content is 2%. No external heat is required during the pyrolysis process.
[0050] Application Example 2
[0051] Organic solid waste raw materials: municipal sludge, moisture content 75%, dry basis calorific value 1200kcal / kg, mechanically dehydrated to a moisture content of 50%.
[0052] Biomass raw material: straw, moisture content 25%, dry basis calorific value 3500Kcal / kg.
[0053] Mixing ratio: municipal sludge: straw = 1:3.
[0054] Multi-layer split furnace pyrolysis and distillation parameters:
[0055] Drying zone: consists of three drying modules. The first drying module has a temperature of 250-290°C and a residence time of 8 minutes; the second drying module has a temperature of 300-330°C and a residence time of 8 minutes; the third drying module has a temperature of 360-400°C and a residence time of 8 minutes.
[0056] Retort zone: includes four retort modules, the first retort module temperature is 430-460℃, the residence time is 8 minutes; the second retort module temperature is 480-500℃, the residence time is 8 minutes; the third retort module temperature is 480-510℃, the residence time is 8 minutes; the fourth retort module temperature is 520-550℃, the residence time is 8 minutes.
[0057] Cooling zone: consists of three cooling modules. The first cooling module has a temperature of 510-420°C and a residence time of 8 minutes. The second cooling module has a temperature of 370-280°C and a residence time of 8 minutes. The third cooling module has a temperature of 240-160°C and a residence time of 8 minutes.
[0058] Results: The calorific value of biocoal is 3080Kcal / kg, fixed carbon is 64%, ash is 24%, and moisture content is 2%. No external heat is required during the pyrolysis process.
[0059] Application Example 3
[0060] Organic solid waste raw materials: kitchen waste, moisture content 70%, dry basis calorific value 900kcal / kg, mechanically dehydrated to a moisture content of 50%.
[0061] Biomass raw material: straw, moisture content 25%, dry basis calorific value 3500Kcal / kg.
[0062] Mixing ratio: kitchen waste: straw = 1:2, 2% CaO catalyst is added to the mixture to reduce the tar yield during the pyrolysis of kitchen waste.
[0063] Multi-layer split furnace pyrolysis and distillation parameters:
[0064] Drying zone: consists of three drying modules. The temperature of the first drying module is 250-290℃, and the residence time is 7 minutes. The temperature of the second drying module is 300-330℃, and the residence time is 7 minutes. The temperature of the third drying module is 360-420℃, and the residence time is 7 minutes.
[0065] Retort zone: includes four retort modules, the first retort module temperature is 430-460℃, the residence time is 7 minutes; the second retort module temperature is 480-500℃, the residence time is 7 minutes; the third retort module temperature is 480-510℃, the residence time is 7 minutes; the fourth retort module temperature is 520-550℃, the residence time is 7 minutes.
[0066] Cooling zone: consists of three cooling modules. The first cooling module has a temperature of 510-420°C and a residence time of 7 minutes. The second cooling module has a temperature of 370-280°C and a residence time of 7 minutes. The third cooling module has a temperature of 240-160°C and a residence time of 7 minutes.
[0067] Results: The calorific value of biocoal is 2600Kcal / kg, fixed carbon is 43%, ash is 30%, and moisture content is 2%. The pyrolysis process requires external heating, with natural gas as auxiliary heat, and the natural gas consumption is 5 cubic meters / t of feed.
[0068] Application Example 4
[0069] Organic solid waste raw materials: printing and dyeing sludge, moisture content 60%, dry basis calorific value 2200kcal / kg, mechanical physical dehydration to a moisture content of 50%.
[0070] Biomass raw material: pine sawdust, moisture content 15%, dry basis calorific value 4100Kcal / kg.
[0071] Mixing ratio: printing and dyeing sludge: pine wood chips = 2:1.
[0072] Multi-layer split furnace pyrolysis and distillation parameters:
[0073] Drying zone: consists of three drying modules. The temperature of the first drying module is 260-290℃, and the residence time is 5 minutes. The temperature of the second drying module is 300-330℃, and the residence time is 5 minutes. The temperature of the third drying module is 350-390℃, and the residence time is 5 minutes.
[0074] Retort zone: includes four retort modules, the first retort module temperature is 410-450℃, the residence time is 5 minutes; the second retort module temperature is 460-500℃, the residence time is 5 minutes; the third retort module temperature is 530-580℃, the residence time is 5 minutes; the fourth retort module temperature is 550-600℃, the residence time is 5 minutes.
[0075] Cooling zone: consists of three cooling modules. The first cooling module has a temperature of 580-460°C and a residence time of 5 minutes. The second cooling module has a temperature of 410-320°C and a residence time of 5 minutes. The third cooling module has a temperature of 260-160°C and a residence time of 5 minutes.
[0076] Results: The calorific value of biocoal is 3600Kcal / kg, fixed carbon is 66%, ash is 14%, and moisture content is 2%. No external heat is required during the pyrolysis process.
[0077] From the results of the above application examples, it can be seen that the bio-coal obtained by the method of the present invention has a calorific value of up to 3600 Kcal / kg, an ash content of <25%, and a sulfur content of <0.3%, which is significantly better than traditional organic solid waste products.
[0078] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.
Claims
1. A method for preparing biocoal by coupling organic solid waste with biomass pyrolysis, characterized in that: The following steps are involved: S1. Raw material pretreatment: Dehydrate the organic solid waste mechanically to a moisture content of <50% to serve as the organic solid waste raw material; select biomass with a moisture content of 12%-40% and a dry basis calorific value of 3500-4500 kcal / kg as the biomass raw material; S2. Raw material mixing: organic solid waste raw materials and biomass raw materials are mixed according to calorific value and moisture content to form a mixed raw material. The amount ratio of organic solid waste raw materials to biomass raw materials is such that the moisture content of the mixed raw materials is less than 40% and the average calorific value is greater than 2400Kcal / kg. S3. Drying: The mixed raw materials enter the drying zone on the upper layer of the multi-layer split furnace and are dried at a temperature of 250-400°C to a moisture content of <5% to obtain dry materials; S4, dry distillation: The dried material enters the dry distillation zone in the middle layer of the multi-layer split furnace, and the temperature of the dry distillation zone is controlled at 400-600°C. In an oxygen-deficient atmosphere, it undergoes deep drying, organic matter devolatization, organic matter chain scission carbonization and carbonization molding processes to obtain dry distillation material; S5. Cooling: The dry distillation material enters the cooling zone at the bottom of the multi-layer split furnace and is cooled step by step in an oxygen-free atmosphere to obtain bio-coal.
2. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 1, characterized in that: In step S1, the organic solid waste refers to municipal, printing and dyeing plant or sewage plant sludge with a dry basis calorific value of ≥900kcal / kg, and the biomass refers to sawdust or straw with a moisture content of ≤25% and a dry basis lower calorific value of ≥3500kcal / kg; in step S2, the mass ratio of the organic solid waste raw material to the biomass raw material is 2:(1-6).
3. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 1, characterized in that: The temperature of the drying zone and the retorting zone is adjusted by a heat supply and temperature control system connected to the multi-layer split furnace. The heat supply and temperature control system is connected to one or more burners, and the exhaust gas outlet of the burner is connected to the exhaust gas purification system.
4. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 1, characterized in that: The retorting zone is provided with a steam atomization injection interface for cooling the reaction temperature in the retorting zone and controlling the reaction degree.
5. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 3, characterized in that: The pyrolysis exhaust gas discharged from the drying area outlet is purified and then transported to the burner for secondary combustion and reuse.
6. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 1, characterized in that: The exhaust gas discharged from the cooling zone outlet is fully burned by the burner and then discharged.
7. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 3, characterized in that: The drying zone and retorting zone are composed of one or more standard modules, each of which is provided with a feed port, a discharge port and a combustion interface. The heating and temperature control system is connected to the pipes of each standard module to control the temperature of each standard module, and the material stays in each standard module for 4-10 minutes.
8. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 7, characterized in that: The cooling zone is also composed of one or more standard cooling modules, each of which is provided with a feed port, a discharge port and a combustion interface, and the material stays in each standard cooling module for 4-10 minutes.
9. The method for preparing biocoal by coupling organic solid waste with biomass pyrolysis according to claim 8, characterized in that: The cooling zone is also connected to an external water-cooled cooler in an oxygen-free atmosphere. The bio-coal discharged from the cooling zone is further cooled to a temperature below 60°C by the water-cooled cooler to obtain a bio-coal product.